An Oscillating Water Column (OWC) is a marine renewable energy device, designed to extract power from ocean waters. Generally, the OWC includes a chamber open to the surface of the sea and a turbine. The turbine is required to convert the bi-directional airflow produced by the rising and falling sea surface within the chamber into unidirectional rotary motion, which is then used to power a generator to generate electricity. Impulse type turbines with fixed guide vanes have been developed and minimize reliability issues due to the single moving part within the OWC, the rotor. Impulse type turbines also show improved efficiency across a given operating flow rate when compared to Wells type turbines. However, the fixed guide vanes may cause an obstruction downstream of the turbine, thereby reducing efficiency.
What is needed is an OWC turbine that operates with increased efficiency and reliability.